Key Insights On Surgical Timing In Charcot Neuroarthropathy

The Charcot foot and ankle is a challenging clinical entity for the qualified foot and ankle surgeon. It is a progressive disease with insidious onset. Osteoarthropathy was originally described in 1703 but it wasn’t until 1868 that it was called Charcot neuroarthropathy due to Charcot’s work in linking the disease to tabes dorsalis and neuropathy.1,2 It was Jordan who linked this destructive disease — which is associated with joint dislocation, breakdown and pathologic fracture — with diabetes mellitus.3 Osteoarthropathy has an incidence ranging from 0.16 percent to 13 percent in all patients with diabetes, and may lead to an increased risk of amputation and higher mortality rates.4,5 There have been numerous classification schemes describing Charcot neuroarthropathy. However, the most commonly used classification was described by an American orthopedist in 1966.6 Eichenholtz classified Charcot into three radiographic stages. Stage I. Usually referred to as the developmental or “hot” phase, Stage I Charcot presents with hyperemia and edema. Radiographic findings include joint subluxation, dislocation, debris formation and bony fragmentation. Stage II. Usually referred to as the coalescent phase, Stage II shows debris absorption, sclerosis of bony ends and coalescence of bone fragments. Stage III. Usually referred to as the remodeling phase, Stage III presents with marked decrease in redness and swelling. Radiographic findings include decreased sclerosis, remodeling of bony fragments and fragments fusing to the joint surfaces in an effort to recreate the architecture of the foot. Stage 0. Researchers have recently described this stage as ranging from a clinically warm, edematous and painful foot to one with mild fracture or joint space widening without debris.7-9 In addition to classification, researchers have also described the patterns of Charcot, taking the more commonly affected joints into account.10 A Review Of Key Treatment Considerations Surgical management is generally contraindicated in patients with Stage 0 Charcot or those who have active fragmentation and resorption of bone.11,12 (However, this thought process has been challenged in the recent literature. We will discuss this later in the article.) At these stages, one would utilize conservative management in the form of non-weightbearing casts or total contact casts.4,12,13 Researchers have also reported using bisphosphonates during these phases.14 Saltzman, et. al., recently found that non-operative treatment of Charcot neuroarthropathy was associated with a 2.7 percent annual rate of amputation, a 23 percent risk of requiring bracing for more than 18 months and a 49 percent risk of recurrent ulceration.15 These statistics suggest the need for improved methodology in the treatment of Charcot neuroarthropathy. One must take many factors into account prior to surgical intervention and evaluate the risk versus benefit for each individual. In addition to ensuring a complete history and physical, clinicians should keep in mind that the the vast majority of patients with Charcot neuroarthropathy have diabetes. Accordingly, one should pay special attention to metabolic control, nutrition and the vascularity of the affected extremity.16 Podiatric clinicians should also rule out osteomyelitis. Primary care physicians often mistake Stage 0 or Stage I Charcot for cellulitis with underlying osteomyelitis and will specifically request the foot and ankle surgeon to perform a deep culture with a bone biopsy. If there is no history of an ulcer, we believe clinicians should defer the bone biopsy in order to avoid the possibility of iatrogenic osteomyelitis. If doubt still remains, one should obtain a white blood cell labeled bone scan, which clinicians can correlate with gadolinium enhanced magnetic resonance imaging in order to rule out osteomyelitis. A stepwise approach to radiographic analysis is of the utmost importance. One must address the deformity in order to produce the best surgical outcome. Obtaining hindfoot alignment views along with standard foot and ankle radiographs will aid the surgeon in preoperative planning. Computerized tomography (CT) and magnetic resonance imaging (MRI) have little if any value to surgical planning other than to rule out osteomyelitis. Understanding The Goals Of Charcot Reconstruction There are various goals with Charcot reconstruction. We attempt to create a functionally stable foot that is devoid of prominences that may lead to future ulceration and risk of amputation. Wang identified three main goals: • correct ankle equinus and restore the calcaneal inclination angle; • maintain the rearfoot to leg relationship; and • correct and stabilize the degenerative joints.17 One can achieve these goals with a combination of internal and external fixation, which allows the patient early ambulation with a more rigid construct of the anticipated fusion sites. Employing external fixation along with rigid internal fixation decreases the likelihood of recurrent breakdown of the affected extremity along with the contralateral extremity. According to the literature, breakdown of the contralateral limb occurs in approximately 25 percent of the Charcot neuroarthropathy population.18 Early Arthrodesis: Should We Pursue This For Charcot Patients? As mentioned previously, early arthrodesis in the treatment of Charcot has been reported as contraindicated.11,12 However, recent literature has challenged this thinking. Simon proposed early arthrodesis as an alternative to conservative, non-operative management.19 His study involved a series of 14 patients with Stage I Charcot, all of whom obtained stability, clinical union and anatomic reduction. Wang presented his results of 28 patients who underwent arthrodesis with external fixation.20 All were in the early development stage and all achieved radiographic consolidation. Case studies have described successful arthrodesis of the first metatarsocuneiform joint, midfoot and rearfoot secondary to talonavicular dislocation.21-25 Though the recent literature is replete with reports of early arthrodesis, it is not a new technique as the first reported arthrodesis procedures in Charcot occurred as early as 1939.26 A recent review article evaluated 14 published clinical series of midfoot, rearfoot and ankle arthrodesis procedures.27 These series comprised a total of 254 total procedures with 80.7 percent achieving radiographic fusion in approximately five months on average. Clinical stability, defined as “a stable foot on which a brace, shoe or both could be worn,” was obtained in 92.1 percent of these same subjects. In addition, the researchers reported a 26 percent rate of complications, which included infection, nonunion, malunion, amputation, stress fracture, fixation failure and recurrence of deformity. A history of ulceration and concurrent ulceration increase the risks associated with surgical intervention but they are not an absolute contraindication. It has been reported that patients with Charcot neuroarthropathy and ulceration who undergo reconstruction have a 25 percent infection rate.28 The risk of non-healing ulceration also exists with one report citing that three out of 10 patients with ulceration at the time of reconstruction did not heal normally in the postoperative phase.29 Final Thoughts Surgical intervention in the Charcot foot and ankle is becoming more common and much less restrictive. With the improvements in external fixation as well as the training of foot and ankle surgeons in these techniques, there are few limits when it comes to Charcot reconstruction. Charcot neuroarthropathy remains a challenging clinical entity to treat not only due to its complexity but due to the associated diseases as well. In all cases, one must take proper patient selection and preoperative considerations into account. While difficult, these cases can be satisfying for the patient and surgeon alike. Dr. Barp is a Fellow of the American College of Foot and Ankle Surgeons. He practices at the Iowa Clinic at Iowa Methodist Medical Center in Des Moines. Dr. Nickles is the Chief Resident at Broadlawns Medical Center in Des Moines, Iowa. Dr. Steinberg (pictured) is an Assistant Professor in the Department of Surgery at the Georgetown University School of Medicine inWashington, D.C. Editor’s note: For related articles, visit the archives at www.podiatrytoday.com.